Chouinard 1975.

Methods	Allocation: randomised. Blindness: double. Duration: 12 weeks, preceded by 2 weeks fixed daily dose of 125 mg chlorpromazine. Setting: multi‐centre, Hôpital St‐Jean‐de‐Dieu, Montréal and Hôpital St‐Charles, Joliette (Canada).
Participants	Diagnosis: chronic (ambulatory) schizophrenia. N = 96 (n = 48 relevant). Age: mean ˜ 42 ± 9.3 years. Sex: 48 F, 48 M. History: chronic, outpatient, length of previous hospitalisations ranging from 0.5 to 31.3 years. Included: 20 to 60 years old; primary hospital diagnosis of schizophrenia confirmed by research psychiatrist; presence of two or more of the following symptoms/ behaviours – thought or speech disturbance catatonic motor behaviour; paranoid ideation; hallucinations; delusional thinking other than paranoid; blunted or inappropriate affect; disturbance of social behaviour and interpersonal relations. Excluded: physical illness, childhood schizophrenia, chronic or acute brain syndrome, IQ below 70, alcoholism, epilepsy, drug addiction. Consent: all participants gave informed consent after purpose of study and possible side effects were explained.
Interventions	1. Perphenazine: 20 mg/day, N = 24. 2. Placebo: 5 tablets a day, N = 24. [3. Amitriptyline‐perphenazine: 20 mg/day, N = 24 ‐ not included in data and analysis, not an antipsychotic]. [4. Amitriptyline hydrochloride: 125 mg/day, N = 24 ‐ not included in data and analysis, not an antipsychotic]. Additional medication: procyclidine hydrochloride for parkinsonism, chlorpromazine (orally in liquid form) for extreme agitation.
Outcomes	Leaving the study early: any reason. Mental state: change over time ‐ relapse. Adverse events: Abnormal laboratory results: SGOT, SGPT, alkaline phosphate, cholesterol, total serum bilirubin, fasting blood glucose. Unable to use ‐ Global state: CGI end score (no SD). Mental state: BPRS, IMPS (no SD). Laboratory tests (no data).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised ‐ quote, "within [groups of] 12 patients, individuals were randomly assigned to one of the four treatment drugs" (p1296).
Allocation concealment (selection bias)	Unclear risk	No details.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Double blind ‐ identical‐appearing tablets used. Each participant received one tablet three times per day and two at bedtime.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Of N = 96 entering the study, n = 16 did not complete the full 12‐week course because of, quote, "poor response to treatment...but all completed at least four weeks" (p1299), i.e. those that relapsed. For participants leaving the study early, they were rated before being excluded from the study, and these evaluations were used in the final analysis.
Selective reporting (reporting bias)	High risk	No (useable) data reported for CGI, BPRS, IMPS or laboratory tests (only P values, or df reported).
Other bias	Unclear risk	Funding: no details provided. Raters: not stated to be independent of treatment.